DETERMINING THE SALT TOLERANCE OF TRITICALE DISOMIC ADDITION (THINOPYRUM ADDITIONS) LINES

摘要

Biotic and abiotic stresses constitute an increasing problem, and in arid and semi-aridregions salinity and drought stress are especially severe. Saline soils can be treated,but it is expensive and temporary. An obvious solution is to modify the plant to copewith salinity. Unfortunately the genetic and physiological bases of salt tolerance are notwell understood as the trait is under polygenic control in most crop species includingcereals. Accessible sources of salt tolerance genes are hard to come by. Thinopyrumdistichum (2n = 28) is an indigenous grass native to the coast of the Western Capeprovince of South Africa. A project was initiated to transfer the salt tolerance of thisgrass to commercially cultivated triticale and wheat. Disomic additions were made ofspecific Th. distichum chromosomes believed to contribute to salt tolerance. This studydeveloped and optimized screening techniques to differentiate among these additionlines with the aim of determining their potential contribution to salinity tolerance.Methods included growth and/or yield assessment, detection of damage or tolerancesymptoms, and quantification of physiological changes. The results indicated thatmethods to detect growth or yield reduction gave the best overall correlation with salinitytolerance.